The subject matter disclosed herein relates to filtration and more particularly to air filtration sampling point adaptors for air filtration sampling in gas turbines.
Gas turbines require clean ambient air in order to enhance their performance and prolong their life cycle. To avoid contamination of the air supply into the gas turbine, an air filter is disposed between the ambient air supply and the gas turbines integral air compressor. When the ability to shut down the gas turbine is limited, due to operational commitments such as power generation, pulse filters can be used. Pulse filters are conical shaped filters that rely upon a pulsed jet of air introduced against flow direction to clean them “in operation”. Typically, the air filter includes multiple dust filter cartridges in an array of sufficient media area to cope with the clean air supply requirements of the gas turbine. Over time there is build up of contamination on the filter media dependent upon the dirt loading of the incoming ambient air, which can result in a reduction in airflow and therefore a reduction in performance of the gas turbine. With the application of periodic reverse flow jet pulse during normal forward flow it is possible to clean the filter and maintain the gas turbine efficiency. Typically, a pulse of high velocity air is applied in the reverse flow direction to remove contaminate from the filter media and thus regenerate the filter during normal operation. Filter monitoring probes continuously monitor the quality of air being supplied to the gas turbine. A series of ducts guide the air from the pulse filtration houses to the air compressor of the gas turbine. In order to check that the pulse filters are properly filtering contaminants including moisture and particulates, probes can be placed into the filtered air flow, which can measure the level of contaminants in the filtered air (i.e., clean air side) via attached instrumentation. However, in pulse filtration houses access to the main airflow region has been problematic due to size of the filter house and accessibility of the clean air side of the filter house. Currently, air sampling is achieved by adapting an access hatch within the filter housing (i.e., the ducts) and introducing the probe, which samples air at right angles to the air flow path. This approach is problematic due to the access hatches being generally not in ideal positions (in dead air flow zones or in the dirty air side of the filtration houses).